Alcatraz tower to undergo remodeling

As the tallest structure on Alcatraz Island, the 57-year-old water tower is also the most visible and a contributing feature of the island's National Historic Landmark District designation.

But starting next week, the tower will begin being covered with white tarps, giving the false appearance of a new structure while the tower undergoes $1.1 million in repairs.

A lack of use, inadequate maintenance, and the harsh marine environment have slowly eaten away at the water tower's structural integrity, according to the National Park Service.

The 22-acre island in San Francisco Bay, which is now part of the Golden Gate National Recreation Area, was transferred to the park service in 1972 and opened to the public the following year.

According to the National Park Service, the island and its buildings needed substantial repair and stabilization at that time but efforts to do so have been hampered by a lack of available funding.

Money that was available came in small increments, according to the park service, allowing for only a slow, incremental approach to repairs.

An extensive plan was developed to upgrade the buildings in accordance with the park service's mission of preserving historic resources, according to a 2001 environmental impact study of the project.

The water tower is culturally important, according to the park service, because it is covered with Native American graffiti -- scrawled during an 18-month occupation of the island in the late 1960s and early '70s that helped spark the country's Native American civil rights movement.

Scaffolding has already started to be set up around the tower and repair work is expected to last through April 2012, not including the time it will take to restore the graffiti, Golden Gate National Recreation Area spokeswoman Alexandra Picavet said.

The park service has still been negotiating an agreement with interested parties as to how that graffiti will be preserved.

"It will have to be painted over," Picavet said. "One concept is that it can be repainted or restored."

The water tank sits on six cross-braced steel legs anchored to concrete foundations, and according to the project's environmental study, "corrosion and deterioration of the steel fabric is clearly evident, and several steel members are missing or in a state of disrepair."

According to the park service, without the repairs, the area surrounding the tower would likely have to be closed to protect visitors, workers and wildlife from the tower's eventual failure.

Aside from the public safety hazards posed by deteriorating structures, the repairs are needed to prevent "irreparable damage and loss of important historic resources," according to the environmental study.

Missing or deteriorated steel members will be replaced and the structure will be seismically upgraded before the tower is sanded and repainted.

According to the environmental study, the extent of the necessary seismic repairs will be assessed once the scaffolding has been erected.